In a related-art generator for a vehicle, there is installed a generator control device capable of controlling a field current to be supplied to a field coil, thereby adjusting an output voltage of a generator. Moreover, there exists such a related-art generator for a vehicle having a configuration in which a plurality of generators are installed in one internal combustion engine, and the plurality of generators simultaneously generate electricity (for example, refer to Patent Literature 1).
In particular, in the related art described in Patent Literature 1, a generator control device for a master generator installed in the master generator is configured to transmit a field current on-off control signal for controlling supply of a field current to a field coil of the master generator to a generator control device for a slave generator installed in the slave generator. Moreover, the generator control device for the slave generator is configured to control supply of a field current to a field coil of the slave generator in accordance with the field current on-off control signal received from the generator control device for the master generator. The field current on-off control signal described in Patent Literature 1 corresponds to a PWM signal of the present invention.
Thus, through the configuration of the generator control devices as described above, the generator control device for the master generator and the generator control device for the slave generator can use the same field current on-off control signal to control the supply of the field currents to the field coils. Therefore, the power-generation balance between the master generator and the slave generator can be maintained to be equal.